﻿<p>The <em>IfcCompositeCurveOnSurface</em> is a collection of segments, based on p-curves. i.e. a curve which lies on
the basis of a surface and is defined in the parameter space of that surface. The p-curve segment is a special type of
a composite curve segment and shall only be used to bound a surface.</p>
<blockquote class="extDef">
<p style="font-size:inherit">NOTE Definition according to ISO/CD 10303-42:1992<br>
A composite curve on surface is a collection of segments which are curves on a surface. Each segment shall lie on the
basis surface.</p>
<p style="font-size:inherit">There shall be at least positional continuity between adjacent segments. The
parameterization of the composite curve is obtained from the accumulation of the parametric ranges of the segments. The
first segment is parameterized from <em>0</em> to <em>l<sub>1</sub></em>, and, for <em>i &ge; 2</em>, the
<em>i<sup>th</sup></em> segment is parameterized from</p>
<blockquote><img src="../../../figures/ifccompositecurveonsurface-math1.gif" alt="formula" width="140" height="60"></blockquote>
<p style="font-size:inherit">where <em>l<sub>k</sub></em> is the parametric length (that is, the difference between
maximum and minimum parameter values) of the <em>k<sup>th</sup></em> curve segment.</p>
</blockquote>
<blockquote class="note">Entity adapted from <strong>composite_curve_on_surface</strong> defined in ISO
10303-42.</blockquote>
<blockquote class="history">HISTORY&nbsp; New entity in IFC4.</blockquote>